The present invention relates to an apparatus for diaphragm filtration.
Diaphragm filtration is well known. The use of diaphragm filtration in the prior art has so far been limited to laboratory use for scientific purposes.
The present invention aims to provide an apparatus for diaphragm filtration which is more suitable for use in the industrial field.
The apparatus for diaphragm filtration according to the present invention comprises at least one disc-shaped supporting plate, in which at least at one side, at least one channel is provided. The channel is connected to an outlet and inlet port, preferably arranged diametrically opposite each other at the periphery of the supporting plate. A diaphragm is applied over the channel and supported through a permeable layer, such as a supporting gauze, by a further supporting plate, which is clamped onto the first supporting plate, and which closes off the space taken in by the permeable layer and which space is connected to a filtrate discharge.
In the present invention, the channel is meandrically-shaped in order to obtain a good mixture of the medium to be filtered in the channel.
Also the negative effects of the centrifugal forces on the medium to be filtered are eliminated largely due to the meandrical shape of the channel.
In a further embodiment of the apparatus according to the present invention, two or more meandrically-shaped channels, extending next to each other, are present on a flat side of the supporting plate.
In a still further embodiment of the apparatus which is particularly useful for industrial purposes, a stack of supporting plates is provided, clamped onto each other. The inner plates of the stack are provided at both sides with channels, while between every two succeeding supporting plates a permeable layer is arranged with a diaphragm on both sides thereof, such that the diaphragm adjoins a supporting plate.
In this embodiment, the channels are connected at a supporting plate to a common feed and discharge, radially extending through the thickness of the supporting plate, each being connected to a collecting- and distributing pipe, extending along the stack.
According to another embodiment of the apparatus according to the invention, both of the outer plates of the stack of supporting plates are provided on one side with a channel.
The apparatus according to the invention may be comprised of different materials.
In one preferable embodiment of the apparatus according to the invention, the supporting plates are made of plastic and the stack of supporting plates is enclosed by a metal housing, and more particularly by a steel housing.
The construction of the supporting plates may differ. Thus, it is possible, for example, that the supporting plate is made of one piece.
However, in one preferred embodiment of the inventive apparatus, a supporting plate comprises two discs, which on one flat side are provided with a channel and have their opposite sides which face one another positioned against one another. The disc are enclosed by a supporting ring with feed- and discharge channels.
One preferred embodiment of the present invention will be further described in the following detailed description with reference to the accompanying drawing wherein: